In 802.11 systems, a station (STA) can associate with an access point (AP) by active or passive scanning. In active scanning, the STA sends a probe request and the AP responds with a probe response. In passive scanning, the STA actively listens for the beacon. Both the probe response packet and the beacon contain similar information, such as Timestamp, Beacon Interval, Service Set Identifier (SSID), Supported Data Rate, Frequency Hopping (FH) parameter, Coordination Function (CF) Parameter, Direct Sequence (DS) parameter set and Capability Information set. In either case, the STA associates with the AP after receiving a beacon or a probe response.
Typically, a mobile STA connects to a new AP by acquiring the beacon information and then associating with it. However, this process may take on the order of several hundred milliseconds, which can be a very long gap for certain applications. Some solutions to this problem propose that the STA should pre-authenticate to more than one AP in a certain area to reduce the time needed for authentication. However, these solutions do not reduce the time required to get beacon information via either a beacon or probe response as a beacon generally has approximately a 100 millisecond periodicity.
Typically, a probe request/response mechanism sends multiple probe request messages and the STA waits for the response from the AP(s). Accordingly, collecting the beacon information itself may take anywhere from tens of milliseconds to 100 milliseconds. This time delay may be detrimental to the functioning of certain applications the STA is running.
Therefore, it would be beneficial to provide a method and apparatus for distributing beacon information to STAs without the limitations of conventional mechanisms.